926 research outputs found
Small eta-N scattering lengths favour eta-d and eta-alpha states
Unstable states of the eta meson and the 3He nucleus predicted using the time
delay method were found to be in agreement with a recent claim of eta-mesic 3He
states made by the TAPS collaboration. Here, we extend this method to a
speculative study of the unstable states occurring in the eta-d and eta-4He
elastic scattering. The T-matrix for eta-4He scattering is evaluated within the
Finite Rank Approximation (FRA) of few body equations. For the evaluation of
time delay in the eta-d case, we use a parameterization of an existing Faddeev
calculation and compare the results with those obtained from FRA. With an eta-N
scattering length, fm, we find an eta-d unstable
bound state around -16 MeV, within the Faddeev calculation. A similar state
within the FRA is found for a low value of , namely, fm. The existence of an eta-4He unstable bound state close to
threshold is hinted by fm, but is ruled out by
large scattering lengths.Comment: 21 pages, LaTex, 7 Figure
Possible eta-mesic 3He states within the finite rank approximation
We extend the method of time delay proposed by Eisenbud and Wigner, to search
for unstable states formed by eta mesons and the 3He nucleus. Using few body
equations to describe eta-3He elastic scattering, we predict resonances and
unstable bound states within different models of the eta-N interaction. The
eta-3He states predicted within this novel approach are in agreement with the
recent claim of the evidence of eta-mesic 3He made by the TAPS collaboration.Comment: 10 pages LaTex, 3 figure
Large deflections of circular isotropic membranes subjected to arbitrary axisymmetric loading
Circular membranes with fixed peripheral edges, subjected to arbitrary axisymmetric loading are analyzed. A single governing differential equation in terms of radial stress is used. This nonlinear governing equation is solved using the finite difference method in conjunction with Newton-Raphson method. Three loading cases, namely (1) uniformly loaded membrane, (2) a membrane with uniform load over an inner portion, and (3) a membrane with ring load, are analyzed. Calculated central displacement and the central and edge radial stresses for uniformly loaded membrane, agree extremely well with the classical solution
No classical limit of quantum decay for broad states
Though the classical treatment of spontaneous decay leads to an exponential
decay law, it is well known that this is an approximation of the quantum
mechanical result which is a non-exponential at very small and large times for
narrow states. The non exponential nature at large times is however hard to
establish from experiments. A method to recover the time evolution of unstable
states from a parametrization of the amplitude fitted to data is presented. We
apply the method to a realistic example of a very broad state, the sigma meson
and reveal that an exponential decay is not a valid approximation at any time
for this state. This example derived from experiment, shows the unique nature
of broad resonances
Formulation and Evaluation of Solid Dispersions of Furosemide in Sodium Starch Glycolate
Purpose: This investigation was carried out to determine if a solid dispersion of furosemide in sodium starch glycolate (SSG) would enhance the dissolution properties of the drug. Methods: Solid dispersion of furosemide in SSG was prepared in ratios of 1:1 and 1 (furosemide):2 (SSG) by kneading method. In each case, the solid dispersion was characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and X-ray diffraction (XRD) to ascertain if there were any physicochemical interactions between drug and carrier that could affect dissolution. Tablets containing the solid dispersion were formulated and their dissolution characteristics compared with commercial furosemide tablets. The dissolution studies were performed at 37 ± 0.5oC
and 50 rpm in simulated gastric fluid (pH 1.2). Results: FTIR spectroscopy, DSC, and XRD showed a change in crystal structure toward an amorphous form of furosemide. Dissolution data indicated that furosemide dissolution was enhanced. XRD, DSC, FTIR spectroscopy and dissolution studies indicated that the solid dispersion formulated in 1:2 ratio showed a 5.40-fold increase in dissolution and also exhibited superior dissolution characteristics to commercial furosemide tablets. Conclusion: Solid dispersion technique can be used to improve the dissolution of furosemide Keywords: Solid dispersion, Furosemide, Sodium starch glycolate, Dissolution enhancement, physicochemical characterisationTropical Journal of Pharmaceutical Research Vol. 8 (1) 2009: pp. 43-5
Clinico-social parameters of diabetes among patientsutilizing emergency medical services
Background: Diabetes mellitus (DM) is increasing in its potential in developing countries. Rise in diabetic patients calling emergency medical services (EMS) is expected. It calls for thorough assessment of patients with DM utilizing EMS. In the present study, was to assess magnitude of DM among patients utilizing EMS and its clinico-social parameters.Methods: It was hospital record based observational study of patients calling EMS delivered by a tertiary care hospital in Pune, Maharashtra, India during 1st January 2013 to 31st December 2014. Patients with incomplete records were excluded. A person with medical background was trained to extract required information from hospital records. Patients with previously diagnosed DM were considered those who were on diet, oral hypoglycemic agents or taking insulin therapy and newly diagnosed patients with DM were considered those with the value of glycemia on admission >200 mg/dl in first 24 hours. Data analysis was done using SPSS 15.0 software.Results: 45.8% (894/1951) were Patients with DM out of that 78.19% (699/894) were known to have DM while 28.81% (195/1951) were new cases of DM. 5.1% (100/1951) patients had uncontrolled DM. DM was significantly more in >60 years age group and in urban residents (p<0.001). Patients with DM were significantly more to have breathlessness, altered sensorium and dyspnoea as major purpose to call EMS (p<0.001, <0.001 and 0.045 respectively). Other co-morbidities in the form of Hypertension, other cardiovascular abnormalities, COPD, CKD and history of CVA were significantly more among Patients with DM (p<0.001, except for COPD, p=0.027).Conclusions: There was a high burden of patients with DM on EMS. EMS teams should be well trained to diagnose and manage such emergencies. Mass awareness of screening for DM and its proper management will help to decrease such burden
Hidden evidence of non-exponential nuclear decay
The framework to describe natural phenomena at their basics being quantum
mechanics, there exist a large number of common global phenomena occurring in
different branches of natural sciences. One such global phenomenon is
spontaneous quantum decay. However, its long time behaviour is experimentally
poorly known. Here we show, that by combining two genuine quantum mechanical
results, it is possible to infer on this large time behaviour, directly from
data. Specifically, we find evidence for non-exponential behaviour of alpha
decay of 8Be at large times from experiments.Comment: 12 pages LaTex, 3 figure
Breit Equation with Form Factors in the Hydrogen Atom
The Breit equation with two electromagnetic form-factors is studied to obtain
a potential with finite size corrections. This potential with proton structure
effects includes apart from the standard Coulomb term, the Darwin term,
retarded potentials, spin-spin and spin-orbit interactions corresponding to the
fine and hyperfine structures in hydrogen atom. Analytical expressions for the
hyperfine potential with form factors and the subsequent energy levels
including the proton structure corrections are given using the dipole form of
the form factors. Numerical results are presented for the finite size
corrections in the 1S and 2S hyperfine splittings in the hydrogen atom, the
Sternheim observable and the 2S and 2P hyperfine splittings in muonic
hydrogen. Finally, a comparison with some other existing methods in literature
is presented.Comment: 24 pages, Latex, extended version, title change
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